The Experts below are selected from a list of 234207 Experts worldwide ranked by ideXlab platform
Stephen A Wise - One of the best experts on this subject based on the ideXlab platform.
-
development of an improved standard Reference Material for vitamin d metabolites in human serum
Analytical Chemistry, 2017Co-Authors: Karen W Phinney, Katherine E Sharpless, Stephen A Wise, Susan S C Tai, Mary Bedner, Johanna E Camara, Rosalind R C Chia, Lane C Sander, James H Yen, Rosemary L SchleicherAbstract:The National Institute of Standards and Technology (NIST) has developed Standard Reference Material (SRM) 972a Vitamin D Metabolites in Frozen Human Serum as a replacement for SRM 972, which is no longer available. SRM 972a was developed in collaboration with the National Institutes of Health’s Office of Dietary Supplements. In contrast to the previous Reference Material, three of the four levels of SRM 972a are composed of unmodified human serum. This SRM has certified and Reference values for the following 25-hydroxyvitamin D [25(OH)D] species: 25(OH)D2, 25(OH)D3, and 3-epi-25(OH)D3. The value assignment and certification process included three isotope-dilution mass spectrometry approaches, with measurements performed at NIST and at the Centers for Disease Control and Prevention (CDC). The value assignment methods employed have been modified from those utilized for the previous SRM, and all three approaches now incorporate chromatographic resolution of the stereoisomers, 25(OH)D3 and 3-epi-25(OH)D3.
-
organophosphate and phthalate esters in standard Reference Material 2585 organic contaminants in house dust
Analytical and Bioanalytical Chemistry, 2012Co-Authors: Caroline Bergh, Giovanna Luongo, Stephen A Wise, Conny OstmanAbstract:The levels of 22 phthalate diesters (phthalates) and organophosphate triesters (organophosphates) have been investigated in standard Reference Material 2585 (SRM 2585) "organic contaminants in hous ...
-
certification of nutrients in standard Reference Material 1846 infant formula
Journal of AOAC International, 1997Co-Authors: Katherine E Sharpless, Stephen A Wise, Susannah B Schiller, Sam A Margolis, Jeanice Brown M Thomas, G V Iyengar, Jennifer C Colbert, T E Gills, James T Tanner, Wayne R WolfAbstract:In 1996, the National Institute of Standards and Technology (NIST) released Standard Reference Material 1846 (Infant Formula), which can be used as a control Material for assigning values to in-house control Materials and for validating analytical methods for measurement of proximates, vitamins, and minerals in infant formula and similar matrixes. The SRM was manufactured by preparing a spray-dried formula base containing fat, protein, carbohydrates, and minerals and then combining that formula base with a dry-blend vitamin premix that supplied the vitamins. The Certificate of Analysis for SRM 1846 provides assigned values for concentrations of proximates (fat, protein, etc.), vitamins, and minerals for which product labeling is required by the Infant Formula Act of 1980 and by the Nutrition Labeling and Education Act of 1990. These assigned values were based on agreement of measurements by NIST and/or collaborating laboratories. Certified values are provided for vitamins A (trans), E, C, B2, and B6 and niacin. Noncertified values are provided for solids, ash, fat, nitrogen, protein, carbohydrate, calories, vitamin D, delta-tocopherol, gamma-tocopherol, vitamin B1, vitamin B12, folic acid, pantothenic acid, biotin, choline, inositol, calcium, phosphorus, magnesium, iron, zinc, copper, sodium, potassium, and chloride. Information values are provided for iodine, manganese, selenium, and vitamin K.
-
certification of polycyclic aromatic hydrocarbons in a mussel tissue standard Reference Material srm
Polycyclic Aromatic Compounds, 1997Co-Authors: Stephen A Wise, Lane C Sander, Michele M Schantz, Melinda J Hays, Barbara J Koster, Catherine E Sharpless, Susannah B SchillerAbstract:Abstract Standard Reference Material (SRM) 1974a, Organics in Mussel Tissue (Mytilus edulis), has been issued with certified and noncertified concentrations for 33 polycyclic aromatic hydrocarbons (PAHs). The mussel tissue Material was analyzed using four different analytical techniques based on gas chromatography/mass spectrometry (GC/MS) on different stationary phases and on reversed-phase liquid chromatography with fluorescence detection. The results from the different analytical techniques were combined to provide certified concentrations for 15 PAHs with relative uncertainties typically between 4% and 11%.
-
certification of polycyclic aromatic hydrocarbons in a marine sediment standard Reference Material
Analytical Chemistry, 1995Co-Authors: Stephen A Wise, Michele M Schantz, Melinda J Hays, Bruce A Benner, Susannah B SchillerAbstract:The certification of natural matrix environmental standard Reference Materials (SRMs) at the National Institute of Standards and Technology (NIST) is based on the agreement of results from two or more different analytical techniques. Four different analytical techniques were used for the determination of polycyclic aromatic hydrocarbons (PAHs) in a new marine sediment Reference Material, SRM 1941a, Organics in Mire Sediment. These procedures were based on reversed-phase liquid chromatography (LC) with fluorescence detection, a multidimensional a procedure, and gas chromatography/ mass spectrometry on to stationary phases with different selectivity for the separation of PAH isomers. The results from these four approaches were in good agreement and were combined to provide certified concentrations for 23 PAHs, which represents the largest number of certified concentrations for PAHs in any natural matrix SRM
Ingrid Zegers - One of the best experts on this subject based on the ideXlab platform.
-
Development of a Certified Reference Material for myeloperoxidase-anti-neutrophil cytoplasmic autoantibodies (MPO-ANCA)
Clinica Chimica Acta, 2017Co-Authors: Evanthia Monogioudi, Dana Petronela Hutu, Gustavo Martos, Joanna Sheldon, Pier Luigi Meroni, Heinz Schimmel, Ingrid ZegersAbstract:A serum Certified Reference Material (CRM) for supporting reliable autoimmune diagnostics was recently released by the Institute for Reference Materials and Measurements (IRMM) of the Joint Research Centre of the European Commission. It was produced in collaboration with a Working Group on the Harmonisation of Autoimmune Tests of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC WG-HAT). This Material is aimed at facilitating the standardisation of measurements of anti-myeloperoxidase immunoglobulin G antibodies. The CRM could be used as a common calibrant by clinicians and manufacturers thereby significantly improving the comparability of results from commercial immunoassays used for IgG anti-MPO measurements. This paper provides information on the new CRM and its intended use.
-
characterization of the new serum protein Reference Material erm da470k ifcc value assignment by immunoassay
Clinical Chemistry, 2010Co-Authors: Ingrid Zegers, Joanna Sheldon, Hendrik Emons, Thomas Keller, Wiebke Schreiber, Riccardo Albertini, Soren Blirupjensen, Myron Johnson, Stefanie Trapmann, Giampaolo MerliniAbstract:BACKGROUND: The availability of a suitable matrix Reference Material is essential for standardization of the immunoassays used to measure serum proteins. The earlier serum protein Reference Material ERM-DA470 (previously called CRM470), certified in 1993, has led to a high degree of harmonization of the measurement results. A new serum protein Material has now been prepared and its suitability in term of homogeneity and stability has been verified; after characterization, the Material has been certified as ERM-DA470k/IFCC. METHODS: We characterized the candidate Reference Material for 14 proteins by applying a protocol that is considered to be a Reference measurement procedure, by use of optimized immunoassays. ERM-DA470 was used as a calibrant. RESULTS: For 12 proteins [α2 macroglobulin (A2M), α1 acid glycoprotein (orosomucoid, AAG), α1 antitrypsin (α1-protease inhibitor, AAT), albumin (ALB), complement 3c (C3c), complement 4 (C4), haptoglobin (HPT), IgA, IgG, IgM, transferrin (TRF), and transthyretin (TTR)], the results allowed assignment of certified values in ERM-DA470k/IFCC. For CRP, we observed a bias between the lyophilized and liquid frozen Materials, and for CER, the distribution of values was too broad. Therefore, these 2 proteins were not certified in the ERM-DA470k/IFCC. Different value transfer procedures were tested (open and closed procedures) and found to provide equivalent results. CONCLUSIONS: A new serum protein Reference Material has been produced, and values have been successfully assigned for 12 proteins.
-
first certified Reference Material for cystatin c in human serum erm da471 ifcc
Clinical Chemistry and Laboratory Medicine, 2010Co-Authors: Anders Grubb, Veronica Lindstrom, Soren Blirup, C Schmidt, Harald Althaus, Ingrid ZegersAbstract:The IFCC Working Group for the Standardisation of Cystatin C (WG-SCC), in collaboration with the Institute for Reference Materials and Measurements (IRMM), announces the availability of the new certified Reference Material ERM-DA471/IFCC. The Material was characterised using a pure protein primary Reference preparation (PRP) as calibrant. The PRP was prepared from recombinant cystatin C, and its concentration measured using dry mass determination. The characterisation of ERM-DA471/IFCC was performed by particle enhanced immuno-nephelometry, particle enhanced immuno-turbidimetry, and enzyme amplified single radial immuno-diffusion. The certified cystatin C mass concentration in ERM-DA471/IFCC, if reconstituted according to the specified procedure, is 5.48 mg/L, the expanded uncertainty (k=2) being 0.15 mg/L.
Jeff Sharp - One of the best experts on this subject based on the ideXlab platform.
-
development of a seebeck coefficient standard Reference Material
Journal of Materials Research, 2011Co-Authors: Nathan D Lowhorn, W Wongng, Joshua Martin, M L Green, John E Bonevich, E L Thomas, N Dilley, Jeff SharpAbstract:We have successfully developed a Seebeck coefficient Standard Reference Material (SRM™), Bi2Te3, that is essential for interlaboratory data comparison and for instrument calibration. Certification measurements were performed using a differential steady-state technique on 10 samples (15 measurements) randomly selected from a batch of 390 bars. The certified Seebeck coefficient values are provided from 10 to 390 K, and they are further supported by transient measurements. The availability of this SRM will validate measurement results, leading to a better understanding of the structure/property relationships and underlying physics of potential high-efficiency thermoelectric Materials.
-
development of a seebeck coefficient standard Reference Material
Journal of Materials Research, 2011Co-Authors: Nathan D Lowhorn, W Wongng, Joshua Martin, M L Green, John E Bonevich, E L Thomas, N Dilley, Jeff SharpAbstract:We have successfully developed a Seebeck coefficient Standard Reference Material (SRM™), Bi2Te3, that is crucial for inter-laboratory data comparison and for instrument calibration. Certification measurements were performed using two different techniques on 10 samples randomly selected from a batch of 390 bars. The certified Seebeck coefficient values are provided from 10 to 390 K. The availability of this SRM will validate the measurement accuracy, leading to a better understanding of the structure/property relationships, and the underlying physics of new and improved thermoelectric Materials. An overview of the measurement techniques and data analysis is given.
Susannah B Schiller - One of the best experts on this subject based on the ideXlab platform.
-
certification of nutrients in standard Reference Material 1846 infant formula
Journal of AOAC International, 1997Co-Authors: Katherine E Sharpless, Stephen A Wise, Susannah B Schiller, Sam A Margolis, Jeanice Brown M Thomas, G V Iyengar, Jennifer C Colbert, T E Gills, James T Tanner, Wayne R WolfAbstract:In 1996, the National Institute of Standards and Technology (NIST) released Standard Reference Material 1846 (Infant Formula), which can be used as a control Material for assigning values to in-house control Materials and for validating analytical methods for measurement of proximates, vitamins, and minerals in infant formula and similar matrixes. The SRM was manufactured by preparing a spray-dried formula base containing fat, protein, carbohydrates, and minerals and then combining that formula base with a dry-blend vitamin premix that supplied the vitamins. The Certificate of Analysis for SRM 1846 provides assigned values for concentrations of proximates (fat, protein, etc.), vitamins, and minerals for which product labeling is required by the Infant Formula Act of 1980 and by the Nutrition Labeling and Education Act of 1990. These assigned values were based on agreement of measurements by NIST and/or collaborating laboratories. Certified values are provided for vitamins A (trans), E, C, B2, and B6 and niacin. Noncertified values are provided for solids, ash, fat, nitrogen, protein, carbohydrate, calories, vitamin D, delta-tocopherol, gamma-tocopherol, vitamin B1, vitamin B12, folic acid, pantothenic acid, biotin, choline, inositol, calcium, phosphorus, magnesium, iron, zinc, copper, sodium, potassium, and chloride. Information values are provided for iodine, manganese, selenium, and vitamin K.
-
certification of polycyclic aromatic hydrocarbons in a mussel tissue standard Reference Material srm
Polycyclic Aromatic Compounds, 1997Co-Authors: Stephen A Wise, Lane C Sander, Michele M Schantz, Melinda J Hays, Barbara J Koster, Catherine E Sharpless, Susannah B SchillerAbstract:Abstract Standard Reference Material (SRM) 1974a, Organics in Mussel Tissue (Mytilus edulis), has been issued with certified and noncertified concentrations for 33 polycyclic aromatic hydrocarbons (PAHs). The mussel tissue Material was analyzed using four different analytical techniques based on gas chromatography/mass spectrometry (GC/MS) on different stationary phases and on reversed-phase liquid chromatography with fluorescence detection. The results from the different analytical techniques were combined to provide certified concentrations for 15 PAHs with relative uncertainties typically between 4% and 11%.
-
certification of polycyclic aromatic hydrocarbons in a marine sediment standard Reference Material
Analytical Chemistry, 1995Co-Authors: Stephen A Wise, Michele M Schantz, Melinda J Hays, Bruce A Benner, Susannah B SchillerAbstract:The certification of natural matrix environmental standard Reference Materials (SRMs) at the National Institute of Standards and Technology (NIST) is based on the agreement of results from two or more different analytical techniques. Four different analytical techniques were used for the determination of polycyclic aromatic hydrocarbons (PAHs) in a new marine sediment Reference Material, SRM 1941a, Organics in Mire Sediment. These procedures were based on reversed-phase liquid chromatography (LC) with fluorescence detection, a multidimensional a procedure, and gas chromatography/ mass spectrometry on to stationary phases with different selectivity for the separation of PAH isomers. The results from these four approaches were in good agreement and were combined to provide certified concentrations for 23 PAHs, which represents the largest number of certified concentrations for PAHs in any natural matrix SRM
-
certification of polychlorinated biphenyl congeners and chlorinated pesticides in a whale blubber standard Reference Material
Analytical Chemistry, 1995Co-Authors: Michele M Schantz, Barbara J Koster, Susannah B Schiller, Lisa M Oakley, Stephen A WiseAbstract:A Standard Reference Material (SRM) made from whale blubber has been developed for the validation of methods used for the determination of polychlorinated biphenyl (PCB) congeners and chlorinated pesticides. This Material, which is a frozen blubber tissue homogenate, was analyzed using three different analytical techniques. These techniques were based on gas chromatography with electron capture detection on two stationary phases with different selectivity for the separation of PCB congeners and gas chromatography with mass spectrometric detection. The results from these three techniques were in good agreement and were combined to provide certified concentrations for 27 PCB congeners and 15 chlorinated pesticides.
Karen W Phinney - One of the best experts on this subject based on the ideXlab platform.
-
development of an improved standard Reference Material for vitamin d metabolites in human serum
Analytical Chemistry, 2017Co-Authors: Karen W Phinney, Katherine E Sharpless, Stephen A Wise, Susan S C Tai, Mary Bedner, Johanna E Camara, Rosalind R C Chia, Lane C Sander, James H Yen, Rosemary L SchleicherAbstract:The National Institute of Standards and Technology (NIST) has developed Standard Reference Material (SRM) 972a Vitamin D Metabolites in Frozen Human Serum as a replacement for SRM 972, which is no longer available. SRM 972a was developed in collaboration with the National Institutes of Health’s Office of Dietary Supplements. In contrast to the previous Reference Material, three of the four levels of SRM 972a are composed of unmodified human serum. This SRM has certified and Reference values for the following 25-hydroxyvitamin D [25(OH)D] species: 25(OH)D2, 25(OH)D3, and 3-epi-25(OH)D3. The value assignment and certification process included three isotope-dilution mass spectrometry approaches, with measurements performed at NIST and at the Centers for Disease Control and Prevention (CDC). The value assignment methods employed have been modified from those utilized for the previous SRM, and all three approaches now incorporate chromatographic resolution of the stereoisomers, 25(OH)D3 and 3-epi-25(OH)D3.
-
development of a standard Reference Material for metabolomics research
Analytical Chemistry, 2013Co-Authors: Karen W Phinney, Mary Bedner, Johanna E Camara, Guillaume Ballihaut, Brandi Benford, Steven J Christopher, Clay W Davis, Nathan G Dodder, Gauthier Eppe, Brian E LangAbstract:The National Institute of Standards and Technology (NIST), in collaboration with the National Institutes of Health (NIH), has developed a Standard Reference Material (SRM) to support technology development in metabolomics research. SRM 1950 Metabolites in Human Plasma is intended to have metabolite concentrations that are representative of those found in adult human plasma. The plasma used in the preparation of SRM 1950 was collected from both male and female donors, and donor ethnicity targets were selected based upon the ethnic makeup of the U.S. population. Metabolomics research is diverse in terms of both instrumentation and scientific goals. This SRM was designed to apply broadly to the field, not toward specific applications. Therefore, concentrations of approximately 100 analytes, including amino acids, fatty acids, trace elements, vitamins, hormones, selenoproteins, clinical markers, and perfluorinated compounds (PFCs), were determined. Value assignment measurements were performed by NIST and the ...
-
development of a standard Reference Material for vitamin d in serum
The American Journal of Clinical Nutrition, 2008Co-Authors: Karen W PhinneyAbstract:The most widely used indicator of vitamin D status is the measurement of 25-hydroxyvitamin D [25(OH)D] in either serum or plasma. Several studies have reported discrepancies between the results of assays used to measure 25(OH)D, however, which calls into question the ability of 25(OH)D assays to reflect accurately the vitamin D status of individuals. The National Institute of Standards and Technology has been working with the National Institutes of Health's Office of Dietary Supplements to develop a standard Reference Material for circulating vitamin D analysis. This standard Reference Material will provide a Material with stable, well-defined levels of the analytes of interest. Investigators will be able to use the standard Reference Material to validate new analytic methods as they are developed and to assign values to in-house quality-control Materials.
